根据鸟粪层磷灰石的矿化机理,借鉴溶胶-凝胶法选用高化学活性物质的做法,开展了在常温常压条件下制备羟基磷灰石(HA)新方法的研究.结合鸟粪层磷灰石含硅的特点,引入少量的正硅酸乙酯,得到了一种新的抗风化表面保护材料.制备工艺以CaO的乙二醇溶液和P_2O_5的乙醇溶液为前驱体,反应过程常温常压条件下进行,无需调节pH值,操作简单,适合于大面积操作.在汉白玉石材表面使用后,场发射扫描电镜(SEM)、X射线能量色散谱仪(SEM-EDAX)等仪器分析表明所得含硅钙磷酸盐保护膜层与石材结合牢固、结构有序而致密.电导分析表明该保护薄膜能耐受pH=3～4的盐酸的侵蚀,耐酸性良好;对疏松岩石的仿制样品进行加固的结果表明,其抗压强度比空白仿制样品提高了8.5倍:亲水-憎水性检测结果表明,经表面保护的白玉石材与未保护前相比,对水的接触角基本保持不变.为开拓新的石质文物、建筑材料以及山石岩体的保护材料提供了思路.%This work bases on mineralization mechanism of guano layer cellophane, profiting from the sol-gelatin law that usually selects the high chemical activity material during the procedure, engaged in a new method research preparing the hydroxyl apatite under the normal temperature and atmospheric pressure condition (HA). Considered that the guano layer apatite contains silicon, we introduce a small amount of TEOS when prepare the sol. The fields launch scanning electron microscope (SEM), the X-ray energy dispersion spectrometer (SEM-EDAX) and so on instrumental analyses indicate that the surface of white marble stone is firmly combined of dense and orderly structure of calcium phosphate film with silicon component. The craft takes ethylene of CaO glycol solution and ethanol of P_2O_5 solution as precursors and the entire preparation process carries on under the condition of normal temperature and pressure. Also, the process does not need to adjust the pH value and is of simple. Acid resistances, reinforcement and so on hydrophobic are carried to test the thin film. Conductivity analysis shows that this film can sustain pH=3～4 of hydrochloric acid erosion. The reinforcement is enhanced 8.5 times comparing to the blank by the means of compressive strength and hydrophobic basically unchanged. Using this method of preparation of calcium phosphate with silicon component has a good protective effect against decency, suitable for large-scale operation. This work has provided ideas to develop the new protection material of stone cultural relic, building material as well as rock body.
展开▼
